Surgical Treatment of Sanders Type 2 Calcaneal Fractures Using a Sinus Tarsi Approach

Calcaneum is the most commonly fractured tarsal bone. The optimal treatment for displaced calcaneus fractures involving the posterior facet is surgical. The extensile lateral approach is commonly preferred because it provides sufficient exposure of the subtalar facet. However, this technique has the risk of complications such as wound necrosis and sural nerve injury. Various minimally invasive approaches, such as sinus tarsi approach, limited posterior approach, and percutaneous approach, have been introduced to reduce possible complications. This study was prospectively performed to evaluate the results of the sinus tarsi approach for Sanders Type 2 calcaneal fractures using postoperative computed tomography (CT).

Between October 2012 and December 2013, 20 Sanders Type 2 calcaneal fractures were consecutively treated using a sinus tarsi approach and checked using CT preoperatively, immediately postoperatively, and at 12 months after surgery. Clinical evaluations were performed using the visual analog scale (VAS) and the ankle-hindfoot score developed by the American Orthopaedic Foot and Ankle Society (AOFAS). Radiographic evaluations were performed using calcaneus lateral and axial radiographs, hindfoot alignment radiograph, and CT. Changes in Böhler's angles and calcaneal widths were evaluated both preoperatively and at last followup. Reduction of the posterior facet was graded according to articular step, defect, and angulation of the posterior facet in CT.

VAS and AOFAS scores were significantly improved at 1 year after surgery but did not improve further. Böhler's angles and calcaneal widths were significantly improved after surgery. Böhler's angle was significantly smaller at the last followup than immediately after surgery, whereas calcaneal width was maintained. Reduction of the posterior facet was graded excellent in five feet (25%), good in ten (50%), and fair in five (25%) on immediately postoperative CT. Two feet (10%) had transient sural nerve injury which resolved within 3 months. Five feet (20%) had subfibular pain due to a prominent screw heads.

Surgical management using a sinus tarsi approach produced good clinical and radiographic results and low wound complications for Sanders type 2 calcaneal fractures. It is important to have stable fixation and to achieve sufficient reduction of calcaneal width for the prevention of loss of reduction and lateral subfibular impingement.